"We often meet with persons deranged in the matter of love, or hatred, or on the subject of religion, or with respect to property, &c., whilst they are perfectly rational on every other subject; but, if one and the same faculty exercised the various functions of love, and hatred, and religious feeling, &c., and, also, all the other mental functions, it would be impossible for this single faculty to be deranged in the performance of these first-named functions, whilst it was perfectly sane in the exercise of all its other functions: consequently, it is impossible for the mind to consist of only a single faculty" (Fowler, 1839, p. 15).